Project description:We examined global mRNA expression using cDNA microarrays in skeletal muscle of humans before, and 3h and 48h after 300 maximal eccentric contractions. Keywords: Time course Healthy, non-trained university-aged subjects performed 300 single leg maximal eccentric contractions. Skeletal muscle biopsies were taken from the vastus lateralis before, 3h and 48h after the exercise bout. Total RNA was extracted, amplified, reverse transcribed, and cDNA was analyzed on a custom made cDNA microarray. Four subjects were analyzed, and samples were not pooled between subjects (i.e. individual microarrays were used for baseline vs. 3H and baseline vs. 48h for EACH subject; repeated measures design).
Project description:Eccentric exercise (ECC) can result in ultra-structural and histological damage to skeletal muscle. The damage incurred following ECC is typically followed by a subsequent regenerative and adaptive response. The specific mechanisms that drive this response, particularly in human muscle, are not well understood. The objective of this study was to characterize the early molecular response in skeletal muscle following ECC in humans. We used an Agilent whole human genome microarray to assess global gene expression in male subjects (N=35) at 3 hours post-100 eccentric contractions of the knee extensors. ANCOVA (age and BMI covariates) was used to compare mRNA expression between the ECC and non-exercised (CON) legs of each subject. Novel transcripts from IPA identified networks were confirmed with quantitative real-time (qRT)-PCR. qRT-PCR analysis of 3 of these transcripts (IkBα, TNFRSF1A and ICAM-1) confirmed changes observed in the microarray analysis. 35 male subjects performed an eccentric exercise protocol consisting of 100 maximal eccentric contrations of the knee extensors. 3 hours after the completion of the exercise regimen, a muscle biopsy was taken from the vastus lateralis of both legs. The non-exercised leg served as the control. Gene expresssion was analyzed using an ANCOVA, with covariates for age and BMI.
Project description:Eccentric exercise (ECC) can result in ultra-structural and histological damage to skeletal muscle. The damage incurred following ECC is typically followed by a subsequent regenerative and adaptive response. The specific mechanisms that drive this response, particularly in human muscle, are not well understood. The objective of this study was to characterize the early molecular response in skeletal muscle following ECC in humans. We used an Agilent whole human genome microarray to assess global gene expression in male subjects (N=35) at 3 hours post-100 eccentric contractions of the knee extensors. ANCOVA (age and BMI covariates) was used to compare mRNA expression between the ECC and non-exercised (CON) legs of each subject. Novel transcripts from IPA identified networks were confirmed with quantitative real-time (qRT)-PCR. qRT-PCR analysis of 3 of these transcripts (IkBα, TNFRSF1A and ICAM-1) confirmed changes observed in the microarray analysis.
Project description:Full title: Eccentric exercise activates novel transcriptional regulation of hypertrophic signaling pathways not affected by hormone changes. Unaccustomed eccentric exercise damages muscle tissue stimulating mechanisms of recovery and remodeling that may be affected by cellular protection by the sex hormone 17β-estradiol (E2). Using cDNA microarrays, we screened for differences in mRNA expression caused by E2 and eccentric exercise. After randomly assignment to 8 days of either placebo (CON) or E2 (EXP), eighteen men performed 150 single-leg eccentric contractions. Muscle biopsies were collected at baseline (BL), following supplementation (PS), +3 hours (3H) and +48 hours (48H) after exercise. Serum E2 concentrations increased significantly with supplementation (P < 0.001) but did not affect microarray results. Exercise led to early transcriptional changes in striated muscle activator of Rho signaling (STARS), Rho family GTPase 3 (RND3), mitogen activated protein kinase (MAPK) regulation and the downstream transcription factor FOS. Targeted RT-PCR analysis identified concurrent induction of negative regulators of calcineurin signaling RCAN (P < 0.001) and HMOX1 (P = 0.009). Protein contents were elevated for RND3 at 3H (P = 0.02) and FOS at 48H (P < 0.05). These findings indicate that early RhoA and NFAT signaling and regulation are altered following exercise for muscle remodeling and repair, but are not affected by E2.
Project description:Desmin is a cytoskeletal protein in muscle involved in integrating cellular space and transmitting forces. In this study we sought to determine the combinatory effects of desmin deletion, aging and eccentric exercise on skeletal muscle at the transcriptional level across many pathways of muscle physiology.
Project description:We examined global mRNA expression using cDNA microarrays in skeletal muscle of humans before, and 3h and 48h after 300 maximal eccentric contractions. Keywords: Time course